Method for providing a cheese by adding a lactic acid bacterial starter culture to the cheese curd

ABSTRACT

The present invention relates to the field of cheese manufacturing. In particular, there is provided a novel method for making cheese involving the preparation of a cheese curd using a curdling agent and wherein a lactic acid bacterial starter culture is introduced into the resulting cheese curd. The advantage of the present method is that is possible to produce a large amount of cheese curd which may subsequently be divided into smaller portions each of which can be inoculated with specific and designed lactic acid bacterial starter culture to obtain different types of cheese or different ripening profile (storage time) for the same cheese type. Thus, this method is useful in the manufacturing of a variety of cheese types originating from a single curd.

This application is a National Stage Filing of PCT/DK01/00284 filed Apr.27, 2001, which claims the benefits of Provisional Application No60/200,349 filed Apr. 28, 2000.

FIELD OF THE INVENTION

The present invention relates to the field of cheese manufacturing. Inparticular, there is provided a novel method for providing a cheesewherein the cheese curd is prepared by using a curdling agent and wheresubsequently a lactic acid bacterial starter culture is added to thecheese curd. The method is useful in the manufacturing of a variety ofcheese types originating from a single curd.

TECHNICAL BACKGROUND OF THE INVENTION

Cheese is a fresh or ripened dairy product consisting predominantly ofvarying amounts of coagulated milk proteins, fat, water and salts. Thereis an enormous variety of cheese types of different regional origins,traditions of consumption, chemical composition, texture, taste, flavourand shelf life. Thus, processes for making cheese are different for eachdifferent type of cheese to be made.

In principle, there are a number of main steps in the cheesemanufacturing process which are essentially the same for all cheeses:Generally, milk intended for the cheese making is pasteurised, i.e.subjected to a heat treatment to kill pathogens and spoilage bacteriasuch as coliform bacteria which may spoil the cheese by producing largeamounts of gas and an unpleasant flavour. The milk is then usuallystandardised in order to obtain the appropriate ratio of componentswhich is specific for the particular cheese variety.

Subsequently, a microbial starter culture and a milk clotting agent areadded to initiate a specific enzymatic proteolysis of milk proteinsleading to the destabilisation of the casein micelles and consequentlyto the coagulation of the milk. Milk clotting agents include nativeenzymes derived from microbial or animal tissue sources, or the enzymesmay be provided as gene products of recombinant cells expressing a milkclotting enzyme of animal or microbial origin.

Starter cultures are often cultures of acid-producing bacteria which areadded to the cheese milk in order to provide the pH, desired taste,aroma and texture of the resulting cheese and to reduce the pH of thecheese milk as the activity of the added milk clotting enzyme is higherin acidic media. Furthermore, the reduction in pH brought about by themetabolism of the starter culture organism inhibits the growth ofundesirable microorganisms and prevents biochemical reactions.

In addition to the production of acids and flavour compounds, thestarter culture organisms also produce and/or contain proteases,peptidases and aminopeptidases that, like a milk clotting agent, degradethe proteins and carbohydrates present in the milk, in a non-specificmanner, and which is important for the ripening of the cheese.

After an appropriate time interval, during which the coagulum is cut andstirred, allowing for sufficient syneresis, the whey is drained off. Theremaining material is referred to as a curd. Depending on the kind ofcheese to be made, the curd is subsequently pressed into a shape andconsistency that are characteristic for the particular type of cheeseand usually transferred to a brine solution in order to be salted. ThepH of a traditional curd is between pH 5.6 and 6.4. Finally, the curd iskept under conditions where the curd undergoes a ripening process toobtain the finished cheese, and the end pH in the cheese will reach 4.9to 5.3 within the first 48 hours, due to the metabolic activity of thestarter culture.

In order to accelerate the ripening of the cheese, which is initiated bythe selected starter culture added to the cheese milk, a ripening agent,such as a microorganism or an enzyme may be added to the cheese milk orto the cheese curd. Thus, a ripening agent is only added in addition toa starter culture and/or milk clotting agent.

The choice of starter culture organism is based on tradition, theflavour and texture desired in the cheese and the rate and extent ofacid development desired during the entire manufacturing process and inthe finished cheese. Useful commercial dairy starter cultures aregenerally composed of lactic acid-producing lactic acid bacteria. In thepresent context, the expression “lactic acid bacteria” designates agroup of Gram-positive, catalase negative, non-motile, microaerophilicor anaerobic bacteria, which ferment sugar with the production of acidssuch as lactic acid as the predominantly produced acid, acetic acid,formic acid and propionic acid. The industrially most useful lactic acidbacteria are found among Lactococcus species, Streptococcus species,Enterococcus species, Lactobacillus species, Leuconostoc species andPediococcus species. The starter culture organisms will continue toferment sugar until conditions within the cheese prevent it, i.e.unfavourable pH, salt and/or temperature conditions. As the activitiesof the starter culture organism in general is desired throughout thewhole cheese process, i.e. both during the coagulation of the milkproteins and during cheese ripening, the conditions within and aroundthe cheese are carefully selected in order to prevent the killing of allthe added organism.

It is evident from the above description of the traditional cheesemaking process that the different activities of the added starterculture organism to the cheese milk initiate the cheese ripeningprocesses and thus to a large extent determine the pH, taste, flavour,aroma and texture characteristic of the resulting cheese curd and cheesetype. This means that the type of cheese is determined at an early stageof the process namely when the starter culture is added to the cheesemilk.

The dairy plant must therefore decide at an early stage of the cheesemaking process, i.e. prior to adding the starter culture to the cheesemilk, which type of cheese it is desired to make. This implies that thedairy plant is restricted to produce only one type of cheese at a timeand/or one type of cheese for each processing line. However, in thedairy industry there is a clear trend towards larger production units,which are designed to produce cheese at the shortest possible time,which are more cost effective and flexible and which can be operatedwith little manpower.

It is therefore an important objective of the present invention toprovide an improved method of providing a cheese, which is adapted tothe increasing demand for higher flexibility in the modern cheeseproduction. The present method gives the dairy plant the possibility ata later stage, i.e. after the cheese curd has been obtained and/or atthe ripening stage of the cheese curd, of the cheese manufacturingprocess to decide which cheese type to produce. Furthermore, the presentmethod implies that the dairy plant can produce a range of differenttypes of cheese based on a single batch of cheese curd. In addition,more curd per working hour can be produced using the same equipment,automation of the process can be introduced more readily and be usedmore safe/homogeneous with less hazards and bacteriophage attacks, whichare a common problem in traditional cheese production methods, can beeliminated. Furthermore, the method provided herein implies that thedairy plant operators can more easily control the ripening of thecheese.

The method according to the present invention is based on the surprisingfindings that the cheese type can be determined at a later stage of thecheese manufacturing process by initially preparing a cheese curd usinga curdling agent and subsequently, after the curd has been obtained,introducing into the cheese curd a lactic acid bacterial starter culturein order to bring about the main ripening of the cheese, the activity ofwhich culture is thereby determining the desired pH, texture and sensoryparameter such as taste, flavour and aroma of the resulting cheese. Asthe lactic acid bacterial starter culture is introduced into the cheesecurd, the taste and texture characteristic of the resulting cheese aredetermined at a late stage of the cheese making process. This impliesthat it is possible to produce one large batch of cheese curd which maysubsequently be divided into smaller portions each of which can beinoculated with different conventional or specifically designed lacticacid bacterial starter culture to obtain different types of cheese ordifferent ripening profile (storage time) based on the same cheesestarting material.

Various processes for preparing a cheese are known in the art wherein acheese ripening agent, e.g. a mould or an enzyme such as a lipase, isadded to a conventionally produced curd prior to ripening. DE 195 46 345describes a method for the manufacturing of Blue cheese. According tothe traditional Blue cheese manufacturing, e.g. the Danablue process, astarter culture organism, a milk clotting agent and spores of P.roqueforti are added to the cheese milk subsequent to the coagulationand salting steps the resulting cheese curd is exposed to air due topiercing of the cheese. In DE 195 46 345 the fungal spores are added incombination with the piercing. Besides focusing on giving the bestopportunities for the P. roqueforti spores to survive in the Bluecheese, this process involves the use of a traditional cheese curdprepared by using a traditional starter culture and a milk clottingagent added to the cheese milk.

Another example of a cheese manufacturing process is described in U.S.Pat. No. 3,973,042 wherein a mixture of a microbial lipase and spores ofP. roqueforti is added to a traditionally produced cheese curd afterdraining off the whey. In this disclosure the lipase is important forobtaining the characteristic rancid taste in the Blue cheese.

Accordingly, the cheese industry has until now not been in thepossession of a process for the manufacturing of cheese wherein a lacticacid bacterial starter culture is added to the cheese curd. Thus, it hasuntil now not been possible to determined the cheese type at a late ordifferent stage of the process by adding a lactic acid bacterial starterculture to the cheese curd. Reason for this may be traditional way ofthinking and conservatism in the cheese industry as it is not common tochange the old traditional cheese-manufacturing processes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram showing the process steps in the preparation ofa cheese curd using glucono delta lactone and a milk clotting agent.

FIG. 2 is a flow diagram showing the process steps in the preparation ofa cheese curd using glucono delta lactone and lactic acid.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a method for providing acheese, the method comprising the steps of

-   -   (i) adding a curdling agent to a cheese milk,    -   (ii) carrying out conventional cheese curd preparing steps,    -   (iii) adding to the resulting cheese curd of step (ii) a lactic        acid bacterial starter culture,        and keeping the cheese curd resulting from step (iii) under        ripening conditions to obtain he cheese.

DETAILED DISCLOSURE OF THE INVENTION

Thus, in its broadest aspect the present invention provides a method forproviding a cheese by adding to a cheese curd a lactic acid bacterialstarter culture determining the desired pH, sensory parameters andtexture of the resulting cheese. This implies, that a starter cultureoptionally added to the cheese milk as a curdling agent, in contrast tothe conventional cheese technology, is not the primary factordetermining the pH, sensory parameters and texture of the resultingcheese. This effect is, in accordance with the present invention,shifted to the lactic acid bacterial starter culture which is addedafter the curd has been obtained.

In accordance with the invention, the cheese curd is provided by addinga curdling agent to the cheese milk. In the present context, theexpression “curdling agent” relates to any compounds, substances ormicroorganism which, when added to the cheese milk, is capable ofclotting the milk proteins. However, in contrast to a conventionalstarter culture used in accordance with the conventional cheesemanufacturing technology the curdling agent is not the primary or soleagent determining the pH, texture and sensory parameter such as taste,flavour and aroma of the resulting cheese. In preferred embodiments, thecurdling agent is an agent selected from the group consisting of anenzyme, a microorganism and an acid or a combination of one or more ofthese agents.

In the present context, the term “cheese curd” is used interchangeablywith the term “coagulum” and relates to the material remaining after thecoagulation of the milk proteins and draining off the whey. Inaccordance with the invention the cheese curd can be prepared from anytype of milk or milk component including e.g. cow's milk, buffalo milk,goat's milk or sheep's milk. Additionally, such a curd may contain wheyor any milk ingredient substitutes e.g. butter fat replacements likeplant oil or vegetable proteins. Prior to use, the milk may be treatedin such a manner that the milk has a low content of spoilagemicroorganisms. Accordingly, the milk can be pasteurised or the milk canbe treated by a combination of centrifugal separation andmicrofiltration or any other conventional method for treating orstandardising the cheese milk.

In accordance with the invention, the acidification and coagulation ofthe milk may be initiated by chemical acidification or by adding amicrobial starter culture, such as a conventional or specificallydesigned lactic acid bacterial culture. Useful compounds for thechemical acidification of the cheese milk include any food grade acid,which is allowed for the use in food or feed products such as e.g.lactic acid, acetic acid, citric acid or glucono delta lactone. It wasfound that lowering the pH in the cheese milk caused sufficientdestabilisation of the casein to result in coagulation or clotting ofthe milk proteins. Thus, in one preferred embodiment of the methodaccording to the present invention, the cheese curd is prepared byacidifying the milk to a pH which is less than pH 6.7, such as less thanpH 6.5, e.g. less than pH 6.2, including less than pH 6.0, such as lessthan pH 5.7, e.g. less than pH 5.5, including less than pH 5.2, such asless than pH 5.0, e.g. less than pH 4.8.

Heating of the cheese milk can enhance or accelerate the coagulation ofcasein. In traditional cheese manufacturing higher temperature is not apossibility, because of the thermal instability of the added starterculture organisms.

However, when the pH in the cheese milk is above pH 5.0 it may undersome circumstances be required to add a milk clotting agent to the milkin order to obtain a sufficient coagulation of the milk proteins. Thus,in one useful embodiment, the cheese curd is prepared by adding a milkclotting enzyme to the cheese milk in addition to the food grade acid orthe microbial starter culture. When used in accordance with the abovemethod any kind of milk clotting agent may be used, such as a nativeenzyme derived from microbial or animal tissue sources or a milkclotting enzyme provided as a gene product of recombinant cellsexpressing a milk clotting enzyme of animal or microbial origin. In oneuseful embodiment, the curd is prepared by adding a milk clotting enzymeto the cheese milk without or by limited acidification of the milk.

In one useful embodiment, the curdling agent added to the cheese milk instep (i) of the present invention is a microorganism which is selectedfrom the group consisting of a bacterial species, a fungal species and ayeast species. Useful bacterial species are lactic acid bacterialspecies such as Lactococcus species including L. lactis and L. cremoris,Lactobacillus species including L. casei, L. paracasei, L. delbrueckii,L. helveticus and L. acidophilus, Bifidobacterium species including B.bifidum, B. lactis and B. longum, Streptococcus species including S.thernophilus and S. faecium, Leuconostoc species including Ln. lactisand Ln. mesenteroides, Micrococcus species, Enterococcus species andPediococcus species. Other useful bacterial species includeBrevibacterium species including B. casei, Staphylococcus species,Arthrobacter species and Corynebacterium species can be used.

Useful cultures of fungi include e.g. Penicillium species such as P.roqueforti and P. candidum, Endothia parasitica, Aspergillus speciessuch as A. niger and Torelospora species such as T. delbrueckii. Yeastspecies which can be useful as a curdling agent in a method according tothe invention include species of Debaryomyces species such as D.hansenii, Geotrichum candidum, Saccharomyces such as S. cerevisiae e.g.in the form of baker's yeast and S. kefir, Kluyveromyces species such asK. maxianus and K. thermotolerans, Candida valida and Torula kefir.Under certain circumstance can it be useful to add as a curdling agent amixture of any of the above bacterial, fungi and yeast species.

One useful embodiment is wherein the cheese curd prior to step (iii) ofthe present method does not contain viable lactic acid bacteria. In thepresent context, the expression “not containing viable lactic acidbacteria” refers to bacteria which have lost their capability toreproduce, but which may still contain active intracellular enzymes, andwhich may affect e.g. the protein or peptide decomposition of the cheesemilk. In one useful embodiment, the cheese curd is prepared by adding alactic acid starter culture organism and a milk clotting enzyme to thecheese milk followed by heating the inoculated milk resulting in theirreversible thermal inactivation of the starter organisms. In onefurther useful embodiment, the lactic acid bacterium is a sensitivebacterium being sensitive to e.g. temperature, pH, bacteriocin such asnisin, or salt. In the present context, the expression “irreversibleinactivation” refers to the killing or lysis of the organism such thatthe resumption of the metabolic activity or the ability to reproduceitself is not possible even after the temperature is lowered. It will beunderstood, that it is possible to use other means to provideunfavourable conditions for the organism in order to irreversiblyinactivate the organism or to provide a curd not containing viablelactic acid bacteria, such as e.g. nisin, high salt concentration or anunfavourable pH or ripening temperature. In accordance with theinvention, the added starter culture organism is preferably active inthe cheese milk for at the most 2 hours, such as at the most 1 hour,e.g. at the most 30 minutes, including at the most 10 minutes, such asat the most 8 minutes, including at the most 5 minutes, e.g. at the most3 minutes, such as the most 2 minutes.

Thus, the starter culture organism added to the cheese milk is onlyallowed to perform its metabolic activities for at very short period inthe cheese process before the organism is inactivated and renderednon-viable as explained above. This is in contrast to the traditionalcheese making process, wherein the starter culture organisms are keptalive essentially during the entire process.

By effectively killing or lysing of the lactic acid starter cultureorganism added to the cheese milk it is the lactic acid bacterialstarter culture subsequently added to the cheese curd which determinesthe type of the finished cheese, and it is the later added lactic acidbacterial culture which is responsible for the overall ripening profile.

In one further useful embodiment, the curdling agent is a lactic acidbacterium, which substantially only produces acids, such as lactic acidor citric acid, and which substantially does not produce flavourcompounds such as acetate, diacetyl, acetoin, acetolactate, acetaldehydeor butanediol or other aromatic compounds or compounds, which maycontribute significantly to the finished cheese.

In one useful embodiment, and as explained above, the cheese curd isdivided before step (iii) in at least two portions each of whereto alactic acid bacterial starter culture is added in step (iii) to obtaindifferent types of cheese. By dividing the cheese curd in smallerportions, the cheese industry has the possibility to add to theindividual curd portions at a late stage of the process a traditional ora specifically designed lactic acid bacterial starter culture to obtaindifferent types of cheese or different ripening profile for the samecheese type.

In preferred embodiments, the cheese curd is a curd which essentiallyhas no flavour or textural characteristics of the finished cheese, andwhich in the present context also is referred to as a “base curd”. Asexplained above and as shown in the below Examples, it is possible toprepare a cheese curd by chemical acidification, bacterial acidificationand optionally, without the addition of a milk clotting agent. Thus, bynot using a starter culture in the traditional sense for the preparationof a cheese curd, the resulting curd does not have the taste and/or thetexture of the cheese to be obtained. Thus, when preparing a cheese curdusing a curdling agent such as an acid, a milk clotting agent and/or astarter culture organism, which is kept alive for only a very short timeand thus essentially does not confer any specific flavour or texturalcharacteristics to the finished cheese, the resulting curd has, incontrast to when using a starter culture in accordance with theconventional cheese manufacturing processes, essentially no flavour ortextural characteristics of the finished cheese. This type of curd isalso useful when divided into smaller portions each of which can beinoculated with a conventional or specifically designed lactic acidbacterial starter culture to obtain different types of cheese ordifferent ripening for the same cheese type originating from the samecheese curd.

A major advantage of the method according to the invention is, whenproviding a cheese curd without the traditional addition of a starterculture and a milk clotting agent to the cheese milk, the fact that thewhey drained off from the cheese curd has maintained some of its highcontent of valuable components, as the whey components are not subjectedto the same degree of degradation by a starter culture, milk clottingagent, added proteolytic enzymes and/or other ripening agents as in thetraditional cheese processes.

In a preferred embodiment, the curdling agent in step (i) of the methodaccording to the invention is added to the cheese milk in combinationwith at least one compound selected from the group consisting of a pHregulating agent, a microorganism, an enzyme, a colouring agent, aprotein, a vitamin, a mineral, a bacterial nutrient, a whey componentand a dietary fibre. In one useful embodiment, the microorganism is onewhich is selected from the group consisting of a bacterial species, afungal species and a yeast species.

In accordance with the invention, after the curdling agent is added tothe cheese milk, conventional cheese curd preparing steps are carriedout in step (ii) of the present method. In the present context, theexpression “conventional cheese curd preparing steps” relates to thecutting and stirring of the coagulated proteins allowing the whey to bedrained off. Accordingly, when the coagulum is sufficiently set, thecheese curd is cut into pieces in order to facilitate the removal of thewhey. When the cheese curd has been cut, the cheese curd pieces arestirred and subjected to a heat treatment, typically for 30 to 120minutes and typically at a temperature in the range of 32 to 60° C. inorder to modify the protein structure for enhanced syneresis and also todestroy certain groups of added microorganisms and undesiredcontaminating microorganisms and to promote acid development. The heattreatment can be carried out by adding hot water to the curd aftercutting at an amount which is typically in the range of 20–50% byweight, calculated on the total weight of the cheese milk, or bytreating the curd in a heated jacketed vessel. Optionally, the resultingcheese curd can be pressed before and/or after the introduction of thecheese ripening agent to confer to the cheese a specific shape andconsistency. The curd can furthermore be obtained by any kind offiltration processes, such as ultrafiltration and microfiltration, andconcentration techniques.

The next step, i.e. step (iii) of the method according to the invention,is the addition of a lactic acid bacterial starter culture to the cheesecurd obtained in step (ii). As already mentioned above, the overall ideaof the present invention is, in contrast to conventional cheesemanufacturing processes, to use a lactic acid bacterial starter cultureat a later stage of the cheese manufacturing process, i.e. after thecheese curd has been obtained and thus to initiate the ripening of thecheese at that stage of the process. Accordingly, the added lactic acidbacterial starter culture is acting as a cheese ripening agent or as acheese conditioning agent, and provides the cheese curd or cheese withthe pH, sensory parameters and textural characteristics associated withthe desired cheese or cheese type. It will be understood, that a mixtureof two or more lactic acid bacteria starter cultures can be added to thecheese curd.

In the present context, the terms “adding”, “introducing” and“injecting” are used interchangeably and relate to the addition orintroduction of the lactic acid bacterial starter culture into thecheese curd by means explained herein below. The result of theintroduction of the lactic acid bacterial starter culture to the cheesecurd is the obtainment of a ripeable cheese curd when the cheese curdresulting in step (iii) of the present method is kept under ripeningconditions. In the present context, the expression “ripeable cheesecurd” relates to a cheese curd which, when placed under appropriateripening conditions, is capable of undergoing ripening into thespecifically desired cheese type. It will be appreciated that theexpression “ripening conditions” relates to conditions which permit theripeable cheese curd to ripe into a finished cheese. The temperaturesfor ripening are usually within the range of 2 to 30° C. In one usefulembodiment, the ripeable cheese curd is placed in a vacuum package inorder to allow ripening. Thus, the lactic acid bacterial starter cultureis introduced into the cheese curd in order to give the resulting cheeseits specific characteristics.

In accordance with the present invention, a suitable lactic acidbacterial starter culture is one which confers to the cheese curd thedesired pH, flavour and/or textural characteristic as it has beenexplained above and which is capable of maintaining its andmetabolically activity after introduction into the cheese curd in step(iii) to a degree which results in the desired ripening effect. A usefullactic acid bacterial starter culture is a culture of species selectedfrom the group consisting of Lactococcus species including L. lactis andL. cremoris, Lactobacillus species including L. casei, L. paracasei, L.delbrueckii, L. helveticus and L. acidophilus, Bifidobacterium speciesincluding B. bifidum, B. lactis and B. longum, Streptococcus speciesincluding S. themophilus and S. faecium, Leuconostoc species includingLn. lactis and Ln. mesenteroides, Micrococcus species, Enterococcusspecies and Pediococcus species. Other useful bacterial species includeBrevibacterium species including B. casei and, Staphylococcus species,Arthrobacter species and Corynebacterium species can be used.

It will be understood, that the starter culture organism, when added tothe curd, is added under different conditions than normally, such as alower pH, and thus it may be useful to design a specific starter cultureor a derivative of the above mentioned starter cultures which is capableto perform the desired activities under the cheese curd conditions.Thus, it will be appreciated that such a lactic acid bacterial straincan be selected from the group consisting of a wild-type strain, amutant strain, a metabolically engineered strain or a geneticallymodified strain of any kind of bacterium useful in the dairy industry.As used herein the expression “genetically modified bacterium” is usedin the conventional meaning of that term i.e. it includes strainsobtained by subjecting a strain to conventionally used mutagenisationtreatments including treatment with a conventional chemical mutagen orto spontaneously occurring mutants. Furthermore, it is possible toprovide genetically modified lactic acid bacteria by random mutagenesisor by selection of spontaneously occurring mutants.

From a contamination point of view it is important that the introducedstarter culture is biologically pure, i.e. it should only contain thedesired microorganisms and/or enzymes and no or only few foreignmicroorganisms as contaminating organisms. In dairy productscontamination with undesired or spoilage bacteria, fungi andbacteriophages is particularly serious, as such organisms may attack thelactic acid bacterial starter culture, i.e. the microorganisms,resulting in cheese ripening failures.

As mentioned above the specific selection of the strains for the lacticacid starter culture will depend on the particular cheese to be made.Thus, in a preferred embodiment, the lactic acid bacterial species is aselected species, which is conventionally used in the manufacturing of aparticular cheese type or variety. Such a particular cheese type can beselected from the group consisting of a hard and semi-hard cheesesincluding as examples Danbo, Havarti, Cheddar, Edam, Gouda, Muenster,Gruyére Emmental, Parmesan, Romano and Provolone, a processed cheeseincluding American cheeses and Fondue cheeses, a white cheese includingCamembert, Coulommiers and Brie, a white cheese, a blue cheese includingRoquefort, and a fresh cheese including Feta, cream cheeses, semi-softcheeses, soft cheeses, Neufchatel, Mozzarella and Ricotta. As usedherein the term “hard and semi-hard cheese” refers to a cheese typicallyhaving a moisture content of 55% by weight or less.

In a preferred embodiment, the lactic acid bacterial starter culture isadded to the cheese curd in combination with at least one compoundselected from the group consisting of a pH regulating agent, amicroorganism, an enzyme, a aroma compound, a flavouring agent, acolouring agent, a protein, a vitamin, a salt, a mineral, a bacterialnutrient, a whey component and a dietary fibre. The salt(s) may beselected from an alkali metal salt such as NaCl or a phosphate andalkaline earth metal salts including phosphates, chlorides orcarbonates.

In one useful embodiment, the above mentioned microorganism, which maybe added in addition with the lactic acid bacterial starter culture, isselected from a fungal species, a yeast species and a bacterial species.Useful cultures of fungi include e.g. Penicillium species such as P.roqueforti and P. candidum, Endothia parasitica, Aspergillus speciessuch as A. niger and Torelospora species such as T. delbrueckii. Yeastspecies which can be useful as a cheese ripening agent in a methodaccording to the invention include species of Debaryomyces species suchas D. hansenii, Geotrichum candidum, Saccharomyces such as S. cerevisiaee.g. in the form of baker's yeast and S. kefir, Kluyveromyces speciessuch as K. maxianus and K. thennotolerans, Candida valida and Torulakefir. In accordance with the invention, the culture of microorganismsto be introduced into the cheese curd may comprise a mixture of any ofthe above bacterial, fungi and yeast species.

Useful microorganisms may be wild-type strains as isolated from theirnatural environment. It may, however, be advantageous to use microbialstrains, which have been improved be selection, by mutation or bygenetic recombination according to the methods known in the art. Thespecies are selected from laboratory screening test where the productionconditions for the cheese type concerned are simulated. Also the mixtureof species of microorganisms would be useful in accordance with theinvention.

As mentioned above, it is convenient to use an enzyme in combinationwith a lactic acid bacterial starter culture when added to the cheesecurd in order to improve a ripening effect. Thus, in preferredembodiments, an enzyme is added in a ripeningly effective amountselected from a peptidase, a protease, a lipase and a carbohydrase. Inthe present context, the expression “a ripeningly effective amount”relates to an amount of the enzyme, which is sufficient to obtain thedesired characteristic of the resulting ripened cheese when kept underthe above ripening conditions.

Furthermore, plasminogen activators, plasmin, catalysts or differentkinds of compounds having a proteolytic effects can be introduced intoor added to a cheese curd in combination with the lactic acid bacterialstarter culture in order to confer to the cheese the desired pH, taste,flavour and texture characteristics.

In a preferred embodiment, the lactic acid bacterial starter culturewhen used alone or in combination with other agents, comprises a liquidphase. A useful liquid phase medium is water including tap water,distilled water or deionised water, or it can be any medium which issuitable for suspending a starter culture such as milk, suspensions ofmilk solids, whey or solutions containing a mineral or other nutritionalingredients. The liquid medium can further comprise buffering agentsand/or microbial nutrients.

The liquid phase is preferably a sterile medium, which is provided byusing only sterile ingredients or by subjecting the prepared medium to atreatment whereby contaminating microorganisms are killed or removed.Such treatments include heating at a temperature and for a period oftime, which results in a sterile or substantially sterile medium andfiltering under conditions where microorganisms are separated from themedium.

Typically, the lactic acid bacterial starter culture comprises lacticacid bacteria in a concentration of 10⁵ to 10¹³ CFU per ml. In certainpreferred embodiments, the starter culture comprises at least 10⁵ CFUper ml, at least 10⁶ CFU per ml, at least 10⁷ CFU per ml, at least 10⁸CFU per ml, at least 10⁹ CFU per ml, at least 10¹⁰ CFU per ml, at least10¹¹ CFU per ml or at least 10¹² CFU per ml. Conveniently, the starterculture is prepared from a concentrate of starter organisms containing10⁸ to 10₁₃ CFU per g. Such concentrates may be in the form of a slurryor paste of freshly grown bacterial cells. However, in industrialproduction it may be more convenient to prepare the suspension from afrozen or freeze-dried concentrate of the microorganism(s) optionallycontaining one or more cryoprotective

substances. The volume of the lactic acid bacterial starter culturetypically introduced into the cheese curd is in the range of 1 to 200 mlper kg of cheese curd. In certain preferred embodiments, the volume ofthe starter culture in the method of the invention is at least 2 ml perkg of cheese curd, including at least 3 ml per kg of cheese curd, suchas at least 4 ml per kg of cheese curd, e.g. at least 5 ml per kg ofcheese curd, including at least 8 ml per kg of cheese curd, such as atleast 10 ml per kg of cheese curd. However, in further embodiments thevolume of the starter culture in the method according to the inventionis at least 20, 40, 60, 80, 100, 120, 130 ml per kg of cheese curd or atleast 200 ml per kg of cheese curd. The appropriate volume depends onthe type of cheese to be made and the concentration of the lactic acidbacterial starter culture. It is essential that the volume introduceddoes not exceed the volume, which can be absorbed by the cheese curdwithout conferring to the resulting cheese undesirable wet or soft spotswhich can be recognised by the consumer.

It may be useful to add to the starter culture one or more nutrientswhich support survival and activity of the microorganism. In thiscontext, suitable nutrients may be any nutrient normally used inculturing media for particular microorganisms or the liquid medium maybe a commercial liquid culture medium such as e.g. the conventionallyused tryptic soy broth medium, containing the required nutrients.Typically, such nutrients may be selected from yeast extract, peptidesand amino acids; a carbon source which is selected from amonosaccharide, a disaccharide or a polysaccharide; and a vitamin or amixture of vitamins.

In accordance with the present invention, the lactic acid bacterialstarter culture can be introduced, added or transferred into the cheesecurd by means known in the art or specific apparatus developed for thispurpose. Thus, the advantage is that the starter culture can beintroduced by simple technology, which makes it possible to adapt it toalready existing equipment or production line at the dairy plant.Furthermore, an apparatus for introducing the lactic acid bacterialstarter culture can be placed at any step which involves the processingof the cheese curd and it can be part of the automatic process line.

Depending on the texture of the cheese curd, the lactic acid bacterialstarter culture may be introduced before or after pressing. When thecheese curd comprises cheese curd grains the lactic acid bacterialstarter culture is transferred to the surface of the cheese curd grains.This can be accomplished in accordance with the present invention bydifferent kind of techniques such as spraying, centrifugation, tumbling,mixing or by using different types of pumps. For example, the sprayingtechnique requires the motion of the cheese curd grains in order toplace the lactic acid bacterial starter culture on the surface of thecurd grains. This technique requires means for spraying the starterculture onto the curd grains. In general, the introduction of the lacticacid bacterial starter culture in accordance with any of thesetechniques is performed before pressing the curd or direct at the blockformer.

In an other embodiment of the present invention, the lactic acidbacterial starter culture is introduced onto the cheese curd grains bymixing using e.g. a machine similar to a butter making machine. In thismachine the curd particles, which are transferred to a first workingsection where the curd fines, are mixed with a solution containing thestarter culture. Then the curd and lactic acid bacterial starter cultureare separated in another working section. This separation step can beperformed in different procedures such as using a screw, which separatesthe curd grains from the ripening agent solution and conveys the grainsto the following step in the production (e.g. cutting and pressing). Theflavouring technique from the continuous butter concept could also beused for introducing the lactic acid bacterial starter culture into thehomogenous cheese curd. Applying the cheese curd and starter culture toa centrifuge the same technique of conveying the curd by using a screwas described above can be used. A centrifuge which resembles the buttermaking machine is the decanter centrifuge.

It has been found that it is possible and convenient to introduce thelactic acid bacterial starter culture by means of needles when thecheese curd comprise a firm substance of cheese curd. In the presentcontext, the term “needle” is used in the conventional meaning andrelates to any types of needles such a hollow needle, a hypodermicneedle, a cannula or a syringe needle. It will be appreciated that theform of the needle depends on the dimension of the cheese curd to beinjected. The advantage of using at least one needle for theintroduction of the lactic acid bacterial starter culture into thecheese curd is that it is possible to calculate or determine the amountof starter culture introduced and/or absorbed by the cheese curd.Furthermore, as the starter culture is introduced into the cheese curdthere is only a minor loss of starter culture during the manufacturingprocess. For these systems the treatment with the lactic acid bacterialstarter culture can be performed after cutting and pressing of thecheese curd, in a figurative sense it could e.g. be in the block formeror at other pressing method.

Thus, in one preferred embodiment, the lactic acid bacterial starterculture is added in step (iii) of the method according to the inventionto the cheese curd through at least one hollow needle. Any kind ofneedle can be used in the present apparatus and the physical form of theneedle depends on the dimension of the curd to be injected. In order toobtain a sufficient distribution of the starter culture into the curd orin order to introduce different starter cultures at the same time, itcan be useful to introduce the lactic acid bacterial starter culture bymeans of a multiplicity of needles. It has been found that theintroduction into the cheese curd of 1 to 200 ml per kg of cheese curdis suitable, provided this volume is distributed by multiple injectionssuch as by means of a multiplicity of needles. In particular, a volumewhich is in the range of 1 to 50 ml of the lactic acid bacterial starterculture per kg cheese curd has been found to result in an appropriateabsorption of the starter culture into the cheese curd. In a specificembodiment, the needle comprises at least one nozzle, which increasesthe distribution of the starter culture in the curd.

The invention will now be described in further details in the followingnon-limiting examples.

EXAMPLE 1

Preparation of a Cheese Using Glucono Delta Lactone (GDL) and a MilkClotting Agent (Chymosin) in the Preparation of the Cheese Curd

This example illustrates the preparation of a cheese curd by loweringthe pH with glucono delta lactone (GDL) and by using chymosin as a milkclotting agent. Following these treatments the cheese curd was cut andstirred for draining off whey from the cheese curd. Subsequently thecheese was pressed and a conditioning solution containing at least oneproteolytic enzyme and/or at least one lactic acid bacterial starterculture was injected into the cheese curd in order to initiate thedevelopment of the desired pH, taste flavour, aroma and texture.

The process steps are shown in the flow diagram shown in FIG. 1.

Prior to cheese manufacturing the cheese vat and all equipment used formanufacturing were disinfected with hypochlorite. The cheese milk wassupplemented with 15 gram potassium nitrate (KNO₃) per 100 liter cheesemilk in order to prevent growth of undesirable micro organisms.

Seven different conditioning solutions for introduction into the cheesecurd were used in this Example and contained:

-   -   1. Pure water (control)    -   2. Traditional cheddar starter culture (Chr. Hansen A/S,        Hørsholm, Denmark)        -   Chr. Hansen R-604, cell concentration ≈3*10⁹ CFU./g cheese    -   3. Chr. Hansen A/S designed conditioning mixture        -   Chr. Hansen CR210, cell concentration ≈1*10¹¹ CFU/g cheese        -   Chr. Hansen LHB-02, cell concentration ≈5*10¹⁰ CFU/g cheese        -   Chr. Hansen Brevibacterium casei, cell concentration ≈5*10¹⁰            CFU/g cheese.    -   4. Proteolytic enzyme        -   10 mg of proteolytic enzyme        -   The enzyme was a serine protease from Novo Nordisk A/S,            Bagsværd, Denmark.    -   5. Traditional cheddar culture and the above mentioned Chr.        Hansen A/S designed conditioning mixture (1:1)    -   6. Traditional cheddar culture and proteolytic enzyme (1:1)    -   7. “Crushed” traditional cheddar culture and the above mentioned        Chr. Hansen A/S designed conditioning mixture (1:1)        -   The cell-solution was crushed with a one shot homogeniser,    -   8. “Crushed” traditional cheddar culture, the above mentioned        Chr. Hansen A/S designed conditioning mixture and proteolytic        enzyme (1:1:1)        -   The cell-solution were crushed with a one shot homogeniser.

The flow diagram shown in FIG. 1 shows each individual step in thepreparation of a cheese using GDL and chymosin in the preparation of acheese curd followed by the addition of the conditioning solution. Inthe following the preparation is explained step-wise, according to thenumbers in the flow diagram shown in FIG. 1.

¹The cheese milk was low-pasteurised, non-homogenised whole milk and thecream used for standardisation was high-pasteurised, non-homogenisedcream with 38% fat.

²The inlet temperature was set at 30–31° C. and the stirring devicemoved at very slow speed.

³850 gram of GDL per 100 liters of cheese milk was added to lower the pHto about 5.0–5.1. Stirring was continued at slow speed.

⁴30 ml chymosin per 100 liters of cheese milk was added to coagulate thecheese milk. After one minute of stirring, the stirring equipment wasremoved so that the milk could rest and turn into a gel/coagulum. Thisprocess took about 5 minutes.

⁵The gel would release whey because of syneresis, and this wasaccelerated by cutting the coagel into small cheese cubes (1*1*1 cm).Speeding up the stirring also altered syneresis, first five minutes withdouble speed and subsequently ten minutes at four times faster speed.

⁶Stirring was stopped and the mixture of whey and cheese curd/cubes wasset to rest, and the draining started. 30 liters of whey were drainedoff (corresponding to one third of total cheese milk).

⁷Stirring was subsequently restarted at the high speed for another tenminutes. Meanwhile the mixture of whey and cheese cubes was heated bywarm water being pumped through the jacket of the cheese vat. Thetemperature of the mixture reached about 38° C.

⁸The stirring was continued at the same speed as mentioned above fortwenty minutes. 60 liters of 44–46° C. warm scalding water was addedthrough a nozzle at a flow rate of 10 liter/minute (corresponding to twothirds of total cheese milk).

⁹The cheese coagulum was allowed to settle and the whey was drained off.All whey/water was drained off and the cheese curd was placed on aperforated strainer.

¹⁰Cheese curd was wrapped in a cheese cloth and placed in a hoop. Eachcontainer was filled with 400–500 g cheese. The hoop and lid were madeof perforated stainless steel.

¹¹Cheese curd was pressed five minutes at a pressure of 2 bar. Eachcheese was then removed from its container and unwrapped. Afterwards itwas carefully wrapped again, and turned upside down in the mouldingcontainer.

¹² On top of each cheese a plastic disc was used as a template to centrethe cheese, injection of the conditioning solution was practised byletting a needle penetrate the plastic disc, cheesecloth and cheesecurd. The needle was about 4 cm in length, and each cheese was about 8cm high, meaning that all 4 ml of the conditioning solution wereinjected into the middle of the cheese. The above mentioned sevenconditioning solutions were used, and in total three cheeses wereinjected with the same solution in order to follow maturation.

¹³The plastic discs were removed, and the lid placed on each hoopcontainer. The cheese was placed in the press, and pressed for 20minutes at a pressure of 6 bar.

¹⁴After pressing, each cheese was placed in a vacuum plastic bagtogether with 4 gram of sodium chloride (corresponding to 8–10 g NaClper 1 kg cheese). Then the cheeses were packed using full vacuum(98–100%) and sealed with heat, and further ripening was performed.

¹⁵The cheeses were stored for two weeks at 16° C. and then moved to a 9°C. storage room for further ripening. The cheeses were analysed after 3weeks of ripening.

After storage, the cheeses were subjected to chemical analysis, i.e.measurement of pH of the cheeses and the content of fat, water, NaCl,total nitrogen (NT), pH 4.4 soluble nitrogen (SN).

Results

The cheese manufacturing process was simple and without anycomplication. The cheese curd was easy to handle and the produced cheesewas comparable to traditional semi-hard cheese. The texture was stillrubbery and elastic after 3 weeks maturing. The conditioning solutionworked at the low pH (5.2). Because of the artificial chemicalacidification the taste was slightly affected.

TABLE 1.1 Cheese characteristics after 3 weeks at ripening. Conditioningsolution Variable (measured) No. 2 No. 3 No. 4 No. 5 No. 6 No. 7 No. 8pH 5.09 5.14 5.28 5.12 5.01 5.14 5.24 % moisture ≈42.7 ≈42.7 ≈42.7 ≈42.7≈42.7 ≈42.7 ≈42.7 % salt ≈2.0 ≈2.0 ≈2.0 ≈2.0 ≈2.0 ≈2.0 ≈2.0 % salt inmoisture ≈4.25 ≈4.25 ≈4.25 ≈4.25 ≈4.25 ≈4.25 ≈4.25 % fat ≈31.0 ≈31.0≈31.0 ≈31.0 ≈31.0 ≈31.0 ≈31.0 % dry matter ≈57.3 ≈57.3 ≈57.3 ≈57.3 ≈57.3≈57.3 ≈57.3 % fat in dry matter ≈54.1 ≈54.1 ≈54.1 ≈54.1 ≈54.1 ≈54.1≈54.1 % moisture in non fat ≈61.9 ≈61.9 ≈61.9 ≈61.9 ≈61.9 ≈61.9 ≈61.9substance % Total Nitrogen ≈27.0 ≈27.0 ≈27.0 ≈27.0 ≈27.0 ≈27.0 ≈27.0 %pH 4.6 SN/TN 27.0 28.9 45.5 28.5 46.4 28.0 41.1

According to the % pH 4.6 SN/TN measured, which refers to the degree ofhydrolysis in casein, the results show that controlling of thedevelopment of the characteristics of the cheese such as taste, flavour,aroma and texture is tricky when adding to the cheese curd solutionscontaining proteolytic enzymes. The % pH 4.6 SN/TN numbers for cheesescontaining proteolytic enzymes refers to cheeses, which are more than 7month old. Thus these results demonstrate the necessity of applying alactic acid bacteria starter culture to the conditioning solution forhaving the expected characteristic of the specific cheese. Furthermore,the results demonstrate that it is possible at that stage of the processto initiate the ripening of the cheese and thus the development of thedesires cheese characteristics.

The use of a specifically developed conditioning solution mixture whichhas been developed by Chr. Hansen A/S for accelerating the ripening ofthe cheese, which is initiated by the starter culture and milk clottingagent added to the cheese milk, did not under these conditions provideany additional buster effect to the development of the characteristicsof the cheese compared to a traditional cheddar cheese. This indicatesthe difficulties to decide the culture composition, because theconditions in cheese curd are very much different as media than cheesemilk. The ingredients supplier is not used to pick the starter culturemicroorganisms strain that can work properly/optimal under theseconditions.

EXAMPLE 2

Preparation of a Cheese Using Glucono Delta Lactone (GDL) and LacticAcid in the Preparation of the Cheese Curd.

This example illustrates the preparation of a cheese curd where the pHwas lowered using lactic acid and glucono delta lactone (GDL). Followingthis treatment, the cheese curd was stirred very vigorously to provideheterogeneous cubes of cheese curd and the cheese curd was drained.Subsequently the cheese curd was pressed and the conditioning solutionwas injected into the cheese, thus the cheese can develop the desiredpH, taste flavour, aroma and texture.

The process steps for cheese manufacturing using the above acidificationstep shown in the flow diagram shown in FIG. 2.

Before cheese manufacturing the cheese vat and all equipment used formanufacturing were disinfected with hypochlorite, as explained inExample 1. The milk was supplemented with 15 gram potassium nitrate(KNO₃) per 100 liters of cheese milk.

The same seven conditioning solutions used in Example 1 were also usedin this Example.

The flow diagram shown in FIG. 2 shows each individual step in thepreparation of a cheese using GDL and lactic acid in the preparation ofa cheese curd. In the following, the preparation is explained step-wise,according to the numbers in the flow diagram shown in FIG. 2.

¹The cheese milk was low-pasteurised, non-homogenised whole milk and thecream used for standardisation was high-pasteurised, non-homogenisedcream with 38% fat.

²The inlet temperature was set at 30–31° C. and the stirring devicemoved at very slow speed.

³2850 gram of GDL and 130 ml lactic acid per 100 liters of cheese milkwere added to lower the pH to about 4.5–4.6. Stirring was continued at aslow speed until pH 4.9 was reached, where it was increased about fourtimes.

⁴At pH 4.7 the stirring was speeded up to break down the cheesecoagulum, and heterogenous cubes were formed (if the stirring wasstopped at pH 4.9 the cheese milk would turn into a coagulum at pH4.7–4.6 and cutting would be required to obtain cheese cubes). Thestirring was continued at the high speed for 15 minutes.

⁵Stirring was stopped and the mixture of whey and cheese curd/cubes wasset to rest, and the draining was started. 30 liters of whey weredrained off (corresponding to one third of the total cheese milk).

⁶Stirring was then restarted at moderate speed level for another tenminutes. Meanwhile the mixture of whey and cheese cubes was heated bywarm water pumped through the jacket of the cheese vat. The temperatureof the mixture reached about 38° C.

⁷The stirring was continued at the same speed as mentioned above for afurther twenty minutes more. 60 liters of 44–46° C. warm scalding waterwas added through a nozzle at a flow rate of 10 liters/minute(corresponding to two thirds of total cheese milk).

⁸The cheese curd was settled and the whey was drained off. Allwhey/water was drained off and the cheese curd was placed on aperforated strainer.

⁹The cheese curd was wrapped in a cheese cloth and placed in a hoop.Each container was filled with 400–500 g cheese. The hoop and lid weremade of perforated stainless steel.

¹⁰The cheese was pressed for five minutes at 2 bar. Each cheese was thenremoved from its container and unwrapped. Subsequently, it werecarefully wrapped again, and turned upside down in the mouldingcontainer.

¹¹The injection of the conditioning solution was practised by entering aneedle penetrate the cheese cloth and into the cheese curd. The needlewas about 4 cm in length, and each cheese was about 8 cm high, meaningthat all 4 ml of conditioning solution was injected in the middle of thecheese. The above-mentioned seven different conditioning solutions wereused and in total three cheeses were injected with the same solution inorder to follow maturation.

¹²The plastic discs were removed and the lid placed on each hoopcontainer. The cheese was placed in the press and pressed for 20 minutesat 6 bar.

¹³After pressing, each cheese was placed in a vacuum plastic bagtogether with 4 gram of sodium chloride (corresponding to 8–10 g NaClper 1 kg cheese). Then the cheeses were packed using full vacuum(98–100%) and sealed with heat, and then the further ripening of thecheese is performed.

¹⁴The cheeses were stored two weeks at 16° C. and then moved to a 9° C.storage room for further ripening. The cheeses were analysed after 3weeks of ripening.

After storage, the cheeses were subjected to chemical analyses, i.e.measurement of pH of the cheeses and the content of fat, water, NaCl,total nitrogen (NT), pH 4,4 soluble nitrogen (SN).

Results

The manufacturing process was simple and without complications. Thecheese curd was tough to cut, and therefore stirring was preferred forpromoting syneresis (a consequence of this and the lower pH is moresmaller fines and loss of cream to the whey). The cheese resembles aFeta cheese or cheese curd for cottage cheese. Because of the artificialchemical acidification the taste was affected.

TABLE 2.1 Cheese characteristics after 3 weeks ripening. Conditioningsolution Variable (measured) No. 2 No. 3 No. 4 No. 5 No. 6 No. 7 No. 8pH 4.45 4.36 4.36 4.39 4.44 4.38 4.39 % moisture ≈54.0 ≈54.0 ≈54.0 ≈54.0≈54.0 ≈54.0 ≈54.0 % salt ≈2.5 ≈2.5 ≈2.5 ≈2.5 ≈2.5 ≈2.5 ≈2.5 % salt inmoisture ≈4.6 ≈4.6 ≈4.6 ≈4.6 ≈4.6 ≈4.6 ≈4.6 % fat ≈20.0 ≈20.0 ≈20.0≈20.0 ≈20.0 ≈20.0 ≈20.0 % dry matter ≈46.0 ≈46.0 ≈46.0 ≈46.0 ≈46.0 ≈46.0≈46.0 % fat in dry matter ≈43.5 ≈43.5 ≈43.5 ≈43.5 ≈43.5 ≈43.5 ≈43.5 %moisture in non fat ≈67.7 ≈67.7 ≈67.7 ≈67.7 ≈67.7 ≈67.7 ≈67.7 substance%-Total Nitrogen (TN) ≈21.8 ≈21.8 ≈21.8 ≈21.8 ≈21.8 ≈21.8 ≈21.8 % pH 4.6SN/TN 7.1  5.8  40.4 14.4 36.6 11.6 41.2

This example illustrates that it was possible to manufacture a cheesecurd by using glucono delta lactone (GDL) and lactic acid for loweringthe pH, and without the use of a milk clotting agent.

Thus, after preparing the cheese curd it can be incubated with variesconditioning solutions for providing the cheese of interests.

In the same way as for Example 1, according to % pH 4.6 SN/TN measured,the results again show that controlling of the development of thecharacteristics of the cheese is tricky when adding to the cheese curdsolutions containing proteolytic enzymes. Again the results demonstratesthe necessity of applying a lactic acid bacteria starter culture to theconditioning solution.

The use of a specifically developed conditioning solution mixture whichhas been developed by Chr. Hansen A/S for accelerating the ripening ofthe cheese, which is initiated by the starter culture added to thecheese milk, did only provide a small buster effect to the developmentof the characteristics of the cheese compared to a traditional cheddarcheese, however, it is not as dramatic as the proteolytic enzyme (≈40%)looking at % pH 4.6 SN/TN mesurements. The cheese clotting agent inExample 1 is responsible for some of the development in % pH 4.6 SN/TN.

The reason why the hydrolysis in the casein was lower in this experimentcompared to the hydrolysis of the casein in Example 1 may be sought inthe different pH between the experiments in Example 1 and 2.

1. A method for providing a cheese, the method comprising the steps of(i) adding a curdling agent to a cheese milk, (ii) carrying outconventional cheese curd preparing steps, including draining off thewhey in order to obtain a cheese curd, (iii) adding to the resultingcheese curd of step (ii) a lactic acid bacterial starter culture therebygiving the resulting cheese its specific characteristics, including itsspecific flavour, and keeping the cheese curd resulting from step (iii)under ripening conditions to obtain the cheese.
 2. A method according toclaim 1 wherein the curdling agent is an agent selected from the groupconsisting of an enzyme, a microorganism and an acid.
 3. A methodaccording to claim 2 wherein the microorganism is selected from thegroup consisting of a bacterial species, a fungal species and a yeastspecies.
 4. A method according to claim 3 wherein the bacterial speciesis a lactic acid bacterial species including a Lactococcus species, aLactobacillus species, a Bifidobacterium species, a Streptococcusspecies, a Leuconostoc species, a Micrococcus species, an Enterococcusspecies and a Pediococcus species.
 5. A method according to claim 4wherein the curd prior to step (iii) does not contain viable lactic acidbacteria.
 6. A method according to claim 1 wherein the curdling agent instep (i) is added to the cheese milk in combination with at least onecompound selected from the group consisting of a pH regulating agent, amicroorganism, an enzyme, a colouring agent, a protein, a vitamin, amineral, a bacterial nutrient, a whey component and a dietary fibre. 7.A method according to claim 6 wherein the microorganism is selected fromthe group consisting of a bacterial species, a fungal species and ayeast species.
 8. A method according to claim 1 wherein the lactic acidbacterial starter culture added to the cheese curd in step (iii)comprises a lactic acid bacterial species including a Lactococcusspecies, a Lactobacillus species, a Bifidobacterium species, aStreptococcus species, a Leuconostoc species, a Micrococcus species, anEnterococcus species and a Pediococcus species.
 9. A method according toclaim 8 wherein the lactic acid bacterial species is a speciesconventionally used in the manufacturing of a particular cheese type.10. A method according to claim 9 wherein the lactic acid bacterialspecies is a species conventionally used in the manufacturing of aparticular cheese type selected from the group consisting of a hardcheese, a semi-hard cheese, a semi-soft cheese, a soft cheese, aprocessed cheese, a blue cheese, a white cheese and a fresh cheese. 11.A method according to claim 1 wherein the lactic acid bacterial starterculture in step (iii) is added to the cheese curd in combination with atleast one compound selected from the group consisting of a pH regulatingagent, a microorganism, an enzyme, a aroma compound, a flavouring agent,a colouring agent, a protein, a vitamin, a salt, a mineral, a bacterialnutrient, a whey component and a dietary fibre.
 12. A method accordingto claim 11 wherein the microorganism is selected from the groupconsisting of a bacterial species, a fungal species and a yeast species.13. A method according to claim 11 wherein the enzyme is selected fromthe group consisting of a peptidase, a protease and a lipase.
 14. Amethod according to any of claims 1 to 13 wherein the lactic acidbacterial starter culture is added in step (iii) into the cheese curdthrough at least one hollow needle.
 15. A method according to any ofclaims 1 to 14 wherein the cheese curd before step (iii) is divided inat least two portions each of whereto a lactic acid bacterial starterculture is added in step (iii) to obtain different types of cheese.